Sacrificial layers: an alternative for the conservation of the lime stuccos from Templo Mayor's Structure B in Mexico City

Abstract

Structure B is an archaeological structure from the post-classic period of the Mexica culture located within the archaeological site of Templo Mayor in Mexico City. The various alteration dynamics caused by its exposure to the weather have generated severe conservation problems in the stuccos that cover the reliefs of the stone skulls of Structure B. Since the alteration effects are mainly due to the crystallization of salts, the absorption of direct humidity because of stagnation of water and the impact of rainwater, the use of sacrificial layers is presented as a measure for the long-term conservation of the stuccos. This investigation proposes a methodological framework for the elaboration of diverse models of sacrificial layers, as well as for their qualitative evaluation after submitting them to resistance tests that imitate the environmental dynamics to which the structure is subjected, in order to design a suitable sacrificial layer for a given structure and context.